Characterization of lipoproteins from the turtle, Trachemys scripta elegans, in fasted and fed states

The lipid and apolipoprotein composition of VLDL, IDL, LDL, HDL2 and HDL3 were examined in the turtle, Trachemys scripta elegans, in fasted and fed states. The lipid composition of turtle lipoproteins was very similar to their human counterparts. The major apolipoprotein found in LDL, IDL and VLDL, which has a molecular weight of approximately 550 kD, is a homologue of apoB100. The major apolipoprotein found in both HDL2 and HDL3, has a molecular weight of 28-kD and is homologous to human apoA-I. HDL3 also contains a 6.5 kD protein that is homologous to apoA-II, while HDL2 has two low molecular weight proteins of 6 kD and 7 kD which are also found on the triglyceride rich lipoproteins (TRL). The 7 kD protein is homologous to apoC-III, while the 6 kD protein has a similar size and distribution as apoC-II or apoC-I. In addition, HDL2 also possesses a protein of 15.8 kD that has no obvious mammalian homologue. In both size and apolipoprotein composition, turtle HDL2 resembles human HDL2b while turtle HDL3 resembles human HDL3. In the fasted state, turtles contained very little TRL. When fed a high fat diet, the amount of IDL and LDL sized particles increased significantly. (C) 2003 Elsevier Science Inc. All rights reserved.